Techniques for sonar data processing

Abstract

A sonar system comprising a sonar transmitter, a very large array two dimensional sonar receiver, and a beamformer section transmits a series of sonar pings into an insonified volume of fluid at a rate greater than 5 pings per second, receives sonar signals reflected and scattered from objects in the insonified volume, and beamforms the reflected signals to provide a video presentation and/or to store the beamformed data for later use. The parameters controlling the sonar system are changed so that the beamformer section treats the data from the receiver section with more than one set of parameters. The stream of data is treated either in parallel or in series by different beamforming methods so that at least one beam from the beamformer has more than one value.

1 . A method for recording sonar data measured, the method comprising:
 transmitting, by a sonar system having a beamformer, the beamformer configured with one or more parameters, a plurality of sonar ping into a volume of sonar signal transmitting material;   receiving, by the sonar system, a plurality of signals from one or more objects in the volume of sonar signal transmitting material responsive to a first sonar ping of the plurality of sonar pings;   beamforming, by the sonar system, the plurality of signals under the one or more parameters to generate a first three-dimensional (3D) beamformed sonar data set for the first sonar ping, the first sonar data set describing the one or more objects;   changing, by the sonar system, at least one of the one or more parameters; and   beamforming, by the sonar system and prior to receiving a plurality of second signals responsive to a second sonar ping of the plurality of sonar pings, the plurality of signals under the changed at least one of the one or more parameters to generate a second 3D beamformed sonar data set for the first sonar ping, the second 3D sonar data set describing the one or more objects, the second 3D beamformed sonar data set being different from the first 3D beamformed data set.   
     
     
         2 . The method of  claim 1 , further comprising, identifying a plurality of sub-sections of the first sonar ping, wherein changing the at least one of the one or more parameters comprises changing the at least one of the one or more parameters specific to one of the plurality of sub-sections of the first sonar ping. 
     
     
         3 . The method of  claim 1 , wherein the received plurality of signals are digital data signals converted from acoustic signals for further processing. 
     
     
         4 . The method of  claim 3 , further comprising, storing the digital data signals in a local store. 
     
     
         5 . The method of  claim 3 , further comprising, storing the digital data signals in a remote store. 
     
     
         6 . The method of  claim 1 , further comprising, determining, whether to perform one or multiple types of beamforming analyses to the plurality of signals. 
     
     
         7 . The method of  claim 6 , wherein changing the at least one or more parameters comprises, upon determining to perform multiple types of beamforming analyses, applying a First Above Threshold (FAT) analysis and a maximum amplitude (MAX) analysis on the plurality of signals. 
     
     
         8 . The method of  claim 7 , further comprising, outputting an image representing a combination of the FAT analysis and an image representing the MAX analysis. 
     
     
         9 . The method of  claim 3 , wherein the further processing comprises:
 changing another at least one of the one or more parameters for the first sonar ping; and   beamforming, by the sonar system, the plurality of signals under the changed another at least one of the one or more parameters to generate a third 3D beamformed data set for the first sonar ping, the third 3D beamformed data set describing the one or more objects.   
     
     
         10 . The method of  claim 1 , wherein the one or more parameters includes at least one of a 2D windowing function, a beamforming method, a sidelobe suppression parameter, thresholding parameter, and view parameter. 
     
     
         11 . The method of  claim 10 , wherein the one or more parameters are set to provide sonar data to reconstruct a consolidated image from requested eyepoints of a user. 
     
     
         12 . The method of  claim 10 , wherein changing the at least one of the one or more parameters comprises changing from a cross-section view to a plan view. 
     
     
         13 . The method of  claim 10 , wherein changing the at least one of the one or more parameters comprises changing the beamforming method from a time-domain to a frequency-domain method. 
     
     
         14 . The method of  claim 1 , further comprising, identifying one or more features in the first and second 3D beamformed sonar data sets. 
     
     
         15 . The method of  claim 1 , further comprising, outputting an image from the first 3D beamformed sonar data and an image from the second 3D beamformed sonar data set. 
     
     
         16 . The method of  claim 1 , further comprising, combining, prior to receiving the plurality of second signals, the first and second 3D beamformed sonar data sets to generate a single video frame image. 
     
     
         17 . The method of  claim 16 , further comprising, outputting the single video frame image. 
     
     
         18 . The method of  claim 1 , wherein the sonar data set produced using a sidelobe filter is monitored in real-time to ensure no specified objects are being removed. 
     
     
         19 . The method of  claim 1 , wherein a range of at least one of the first and second 3D beamformed sonar data sets is divided into a number of sections, and a range of one of the objects for each section is recorded or shown as a partial time-series. 
     
     
         20 . The method of  claim 19 , wherein changing the at least one of the one or more parameters comprises changing the sidelobe clip level.